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OBJECTIVES National guidelines in Botswana recommend baseline CD4 count measurement and both CD4 and HIV viral load (VL) monitoring post-antiretroviral therapy (ART) initiation. We evaluated the utility of CD4 count measurement in Botswana in the era of universal ART. METHODS CD4 and VL data were analysed for HIV-infected adults undergoing CD4 count measurement in 2015-2017 at the Botswana Harvard HIV-Reference Laboratory. We determined (1) the proportion of individuals with advanced HIV disease (CD4 count

Estuaries support a wide range of human activities and values, but are one of the most anthropogenically impacted ecosystems in the world. Ki uta ki tai is a holistic view of waterways that is embodied within Ngāi Tahu environmental management, which acknowledges the connectivity between environmental systems and people with the environment. While this philosophy is referred to within current policies, management does not effectively account for or reflect this philosophy. This research evaluated indigenous and local socio-cultural values provided by estuarine shellfisheries across Waitaha/Canterbury and found Ngāi Tahu place-based interaction was impacted by management and anthropogenic inputs. Participants’ estuarine stressors aligned with global stressors. Experienced harvesters/fishers adapted their practices to these stressors, while less experienced harvesters/fishers visited high food-risk sites. Effective management requires identifying the risks to socio-cultural values towards accountability of activities, to meet the ethic of ki uta ki tai.

We study a model for star polymers in solution which, in addition to the ultrasoft repulsive interaction of entropic origin, has an attractive interpolymer interaction at longer range. This attraction can arise from a suitable tuning of the solvent and solute properties. For this model we study the phase diagram using mean-field theory and two fluid-state theories, the modified hypernetted chain (MHNC) integral equation and the hierarchical reference theory, and we explore star polymers with a different number of arms f (f = 12, 24, 32, 40). All three theories give the same topology for the phase diagram in the presence of attraction. When the strength of the interaction is strong enough a fluid–fluid phase transition appears but the coexistence curve in the density–temperature (strength of attraction) bifurcates at a triple point into two lines of coexistence terminating at two critical points. This peculiar phase behaviour is related to the unusual form of the repulsive contribution Vrep (r): at low density and in a semidilute regime the soft-core Yukawa-like part of Vrep (r) is relevant, at higher densities the logarithmic, ultrasoft part of Vrep (r) is the relevant one. During our study we verify that the MHNC equation also gives a very accurate description of correlations for systems with an ultrasoft-core potential.

Compared to pure fluids, binary mixtures display a very diverse phase behavior, which depends sensitively on the parameters of the microscopic potential. Here we investigate the phase diagrams of simple model mixtures by use of a microscopic implementation of the renormalization group technique. First, we consider a symmetric mixture with attractive interactions, possibly relevant for describing fluids of molecules with internal degrees of freedom. Despite the simplicity of the model, slightly tuning the strength of the interactions between unlike species drastically changes the topology of the phase boundary, forcing or inhibiting demixing, and brings about several interesting features such as double critical points, tricritical points, and coexistence domains enclosing `islands' of homogeneous, mixed fluid. Homogeneous phase separation in mixtures can be driven also by purely repulsive interactions. As an example, we consider a model of soft particles which has been adopted to describe binary polymer solutions. This is shown to display demixing (fluid-fluid) transition at sufficiently high density. The nature and the physical properties of the corresponding phase transition are investigated., 6 pages + 3 figures, presented at the 5th EPS Liquid Matter Conference, Konstanz, 14-18 September 2002

The method described in the preceding paper [J. J. Salacuse, A. R. Denton, and P. A. Egelstaff, preceding paper, Phys. Rev. E 53, 2382 (1996)] for computing the static structure factor S(Q) of a bulk fluid is used to analyze molecular dynamics computer simulation data for a model krypton fluid whose atoms interact via a truncated Aziz pair potential. Simulations have been carried out for two system sizes of N=706 and 2048 particles and two thermodynamic states, described by a common reduced temperature ${\mathit{T}}^{\mathrm{*}}$=1.51 and reduced densities ${\mathrm{\ensuremath{\rho}}}^{\mathrm{*}}$=0.25 and 0.4. Results presented include the N-particle radial distribution function ${\mathit{g}}_{\mathit{N}}$(r) and the bulk static structure factor S(Q). In addition we calculate the direct correlation function c(r) from the full S(Q). In comparison with corresponding predictions of the modified hypernetted chain theory, the results are generally in excellent agreement at all r and Q, to within random statistical errors in the simulation data. \textcopyright{} 1996 The American Physical Society.

The hierarchical reference theory (HRT) is applied to the Lennard-Jones fluid below the critical temperature ${\mathit{T}}_{\mathit{c}}$. This study completes a previous one performed above ${\mathit{T}}_{\mathit{c}}$ using the same kind of approximate closure for the direct correlation function. Results for several thermodynamic quantities and for the two-particle correlations are reported and compared both with other theories and with simulation data. In the two-phase region the theory correctly yields rigorously flat isotherms; this feature allows a straightforward and accurate determination of the coexistence curve without resorting to the Maxwell construction. In the critical region our analysis is consistent with the previously developed one for Tg${\mathit{T}}_{\mathit{c}}$ and displays nontrivial critical exponents. We also study a fluid with the Girifalco model potential for ${\mathrm{C}}_{60}$. The critical point of the liquid-vapor transition is found at ${\mathit{T}}_{\mathit{c}}$=2138 K and ${\mathrm{\ensuremath{\rho}}}_{\mathit{c}}$=0.50 ${\mathrm{nm}}^{\mathrm{\ensuremath{-}}3}$. When the HRT result is supplemented with Verlet's freezing criterion a triple point is found at ${\mathit{T}}_{\mathit{t}}$=1979 K and ${\mathrm{\ensuremath{\rho}}}_{\mathit{t}}$=0.848 ${\mathrm{nm}}^{\mathrm{\ensuremath{-}}3}$.

The static structure factor S(k) of liquid krypton has been measured by neutron diffraction at temperatures T=130, 169 and 199 K and at several densities. The extended k range of the measurements, 3.6-160 nm-1, and the high accuracy of the data allow an unambiguous computation of the radial distribution function g(r) and of the direct correlation function c(r). All three functions, S(k), g(r) and c(r), are in remarkably good agreement with the theoretical result when the Aziz pair interaction plus the triple-dipole three-body interaction are used in a triplet MHNC equation. The authors obtain definite evidence that the Lennard-Jones pair potential is not a good representation of the interatomic forces. The small remaining deviation between theory and experiment indicates the presence of some additional many-body force which is repulsive at short distance and attractive at intermediate distance.

The structure factor S(q) and the direct correlation function c(q) of rare gases are expected to have a nonanalytic mod q mod 3 term at small q. This term is due, in addition to the well known long-range r-6 tail of the two-body interaction, also to the three-body Axilrod-Teller interaction. The coefficient c3 of the mod q mod 3 term of c(q) has a particularly simple state dependence, T-1 in temperature and linear in density, when the AT interaction is present. If no three-body interaction is present C3 is density independent. Therefore the experimental determination of the density dependence of c3 will give unequivocable evidence of three-body forces. On the basis of the integral equation method the authors determine that it will be easier to detect the mod q mod 3 term if the scattering data are analysed in term of c(q) and for measurements at density and temperature not far from the critical point. Under these favourable conditions scattering measurements in the range 1-4 nm-1 will give a precise determination of the mod q mod 3 term. The role of retardation, which changes the r-6 tail into r-7, on the small-q behaviour of S(q) and c(q) is also evaluated and this effect is predicted to be measurable for q

A new representation is obtained for the isothermal density derivative ofg(r). It explicitly exhibits the contributions of potential energy terms that are not pairwise additive. Consideration of a previously known result shows that one has to be rather cautious when using it to obtain information on the triplet correlation function from the well-known relation between this function andδg/δρ, due to large cancellations which take place at high density. By integrating with respect to density the new representation forδg/δρ, after a suitable closure has been introduced, we obtain an augmented Percus-Yevick equation for hard spheres which has full thermodynamic consistency. The equation of state and the cavity functiony(r) are very accurate at low density and considerably improve PY at medium density, so that this appears to be a useful new approach to the theory of fluids, but it is necessary to improve the closure in order to treat a dense fluid.

We investigate critical phenomena in colloids by means of the renormalization-group based hierarchical reference theory of fluids (HRT). We focus on three experimentally relevant model systems: namely, the Asakura-Oosawa model of a colloidal dispersion under the influence of polymer-induced attractive depletion forces; fluids with competing short-range attractive and longer-range repulsive interactions; solutions of star-polymers whose pair potential presents both an attractive well and an ultrasoft repulsion at shorter distance. Our results show that the ability to tune the effective interactions between colloidal particles allows one to generate a variety of crossovers to the asymptotic critical behavior, which are not observed in atomic fluids., Comment: 4 pages, 3 figures

We consider symmetric binary mixtures consisting of spherical particles with equal diameters interacting via a hard-core plus attractive tail potential with strengths epsilon_{ij}, i,j=1,2, such that epsilon_{11} = epsilon_{22} > epsilon_{12}. The phase diagram of the system at all densities and concentrations is investigated as a function of the unlike-to-like interaction ratio delta = epsilon_{12}/epsilon_{11} by means of the hierarchical reference theory (HRT). The results are related to those of previous investigations performed at equimolar concentration, as well as to the topology of the mean-field critical lines. As delta is increased in the interval 0 < delta < 1, we find first a regime where the phase diagram at equal species concentration displays a tricritical point, then one where both a tricritical and a liquid-vapor critical point are present. We did not find any clear evidence of the critical endpoint topology predicted by mean-field theory as delta approaches 1, at least up to delta=0.8, which is the largest value of delta investigated here. Particular attention was paid to the description of the critical-plus-tricritical point regime in the whole density-concentration plane. In this situation, the phase diagram shows, in a certain temperature interval, a coexistence region that encloses an island of homogeneous, one-phase fluid., 27 pages + 20 figures

Neutron diffraction measurements and theoretical calculations of the structure factor $S(k)$ of liquid Kr are extended to small k values $(kl4 {\mathrm{nm}}^{\ensuremath{-}1}).$ The results show that many-body interaction contributions have an increasing effect on $S(k)$ as $\stackrel{\ensuremath{\rightarrow}}{k}0,$ reaching at least 40% of the measured intensity. Both the phase diagram and the low-$k$ structural data of dense Kr turn out to be closely reproduced by the hierarchical reference theory if additional many-body forces are taken into account by an augmented strength of the Axilrod-Teller triple-dipole potential. The experimental density derivative of $S(k)$ is also used for a very sensitive test of the theories and interaction models considered here.

We present the results of high-precision measurements of the structure factor S(k) of krypton in the near-critical region of the liquid - vapour phase transition for values of k ranging from 1.5 up to . The experimental results are compared with a theoretical calculation based on the hierarchical reference theory (HRT) with an accurate potential which includes two- and three-body contributions. The theory is based on a new implementation of HRT in which we avoid the use of hard spheres as a reference system. With this soft-core formulation we find a generally good agreement with experiments both at large k, where S(k) probes the short-range correlations, as well as at small k, where critical fluctuations become dominant. Also, for the density derivative of the pair correlation function there is an overall good agreement between theory and experiment.

We show that diffraction measurements can reach the precision needed to test different models of interatomic interaction also in a dense fluid. Our measurements have been performed in krypton at several temperatures and densities in the liquid phase. Our theoretical calculations show that the density derivative of the static structure, contrary to the function itself, is sensitive to the shape of the interaction and the comparison with the experimental data gives another test of the interaction models.

A neutron diffraction experiment has been performed to measure the low-q structure of Kr at liquid densities. Deviations from a pure two-body behaviour are unambiguously determined in the explored q-range (1

We present a study of the correlation length ξ of a hard-core fluid with three different tail interactions, namely, the Asakura–Oosawa potential, an attractive Yukawa tail, and a double Yukawa tail which is attractive at short distance and repulsive at long distance. The correlation length is obtained along the critical isochore in the whole range of supercritical temperatures by determining the leading pole of the structure factor S(k) in the complex plane, where S(k) is obtained from the hierarchical reference theory. We focus on how ξ changes from its Ornstein–Zernike form in the critical region to its high-temperature limit, and find instances of both the Fisher–Widom and Kirkwood scenarios for the monotonic to oscillatory crossover of the decay of correlations at long distance.

A recent perturbation calculation predicting a ‘liquid-gas’ phase separation of charge-stabilized colloidal suspensions is tested against the thermodynamically self-consistent generalized mean spherical approximation. A comparison between the two calculations shows that the perturbation calculation predicts a reasonably accurate critical temperature, but overestimates the critical density. These critical parameters are moreover shown to be rather insensitive to moderate degrees of polydispersity.

Repulsive three-body forces in the presence of strong and very steep two-body attractive forces have a major effect on the phase diagram of a fluid: very low value of the critical density and strong asymmetry of the coexistence curve with an important singular contribution to the diameter. It is suggested that this is the origin of the known peculiarities of the phase separation taking place in micellar solutions.

The modified hypernetted chain and the crossover integral equations for the radial distribution function are generalized to take into account three‐body forces. Good agreement with the simulation results is found. The structure factor and its isothermal density derivative for krypton and argon are computed with a realistic two‐body potential plus the Axilrod–Teller three‐body interaction. For krypton at medium density a very good agreement with experiment if found. At higher densities we find significant deviations both for krypton and for argon. The effect of three‐body forces becomes very significant when the two‐body potential has a narrow attractive well as it is the case in micellar solutions or microemulsions. In particular the critical point can be shifted to a very low value of concentration and there is enhancement of concentration fluctuations for a given value of the correlation length.

The iterative perturbative approach to critical phenomena is applied in EXP approximation to a study of the critical point of a lattice gas model. The iterative relation is studied analytically and also numerically for a finite lattice in the case of single site exclusion with nearest neighbour interaction for a simple cubic and a square lattice. For purpose of comparison this model is also studied in optimized random phase (ORPA) and EXP approximations. We find that the iterative EXP approximation and the non iterated one have the same critical behaviour and this coincides with that of ORPA: all these approximations give spherical model critical phenomena.

The mean spherical approximation (MSA) is found inadequate in the presence of attraction between particles which is strong and of short range compared with the hard core diameter. This is a situation prevalent in applications of liquid state theory to micellar solutions and microemulsions. A generalized MSA is also studied in which conditions of thermodynamic consistency are implemented. The critical point is determined as function of the range of the attractive forces. We also discuss how the inadequacy of MSA affects the effective pair interaction deduced from experimental data for the structure factor.

A m e t h o d , ca l led t h e e ikona l p e r t u r b a t i o n t h e o r y ( E P T ) , ha s r e c e n t l y been de r ived (1.2) a n d p r o p o s e d for i n v e s t i g a t i n g h i g h e n e r g y b e h a v i o u r s in q u a n t u m field t h e o r y (QFT) . Th i s m e t h o d c o m b i n e s t h e a d v a n t a g e s of t h e e ikona l a p p r o x i m a t i o n (EA, see (a.4)) w i t h t hose o f t h e o r d i n a r y p e r t u r b a t i o n t h e o r y (OPT). I n fac t , w h e n se l f in te rac t ions a re o m i t t e d , l owes t -o rde r E P T a m p l i t u d e s c o n t a i n t h e c o r r e s p o n d i n g comple t e E A ampl i tudes , so t h a t , in such cases, t h e E P T shares w i t h t h e E A t h e k n o w n good f ea tu re s for a h i g h e n e r g y a p p r o x i m a t i o n (*). On t h e o t h e r h a n d , as for OPT b u t c o n t r a r y to t he EA, t h e E P T p r o v i d e s a s y s t e m a t i c i t e r a t i v e a p p r o x i m a t i o n in QFT, w h i c h can a c c o u n t for s e l f i n t e r a c t i o n s a n d is r e n o r m a l i z a b l e i f t h e OPT is such . W h e n se l f in te rac t ions are inc luded , t h e E A fails to be a v i ab l e a p p r o a c h (1), whi le i n t e r e s t in t h e E P T , as a h ighe n e r g y a p p r o x i m a t i o n also for processes fa r off shell, is p r o m p t e d b y the resu l t r e c e n t l y de r ived in (5). I n fac t , t h e a s y m p t o t i c b e h a v i o u r of p r o p a g a t o r s , as d i c t a t e d b y renorm a l i z a t i o n g roup a r g u m e n t s (6), was s h o w n (5) to be c o r r e c t l y r e p r o d u c e d b y t he renorma l i zed E P T (7). T h e foregoing cons ide ra t ions emphas i ze t he i m p o r t a n c e of s y s t e m a t i c i n v e s t i g a t i o n s of E P T a m p l i t u d e s and of t h e i r a s y m p t o t i c p r o p e r t i e s : in f ac t , f r om such i n v e s t i g a t i o n s one shou ld be ab le to l e a rn i n t e r e s t i n g h i g h e n e r g y p r o p e r t i e s of QFT ' s , and such p rope r t ies m i g h t p r o v i d e i m p o r t a n t clues for p h e n o m e n o l o g i c a l theor ies of h igh -ene rgy sca t t e r ing . I n t h e p r e s e n t p a p e r we de r ive t h e express ions for ona n d off-shell f o rm fac to r s in lowes t -o rde r E P T . W e discuss t h e r e n o r m a l i z a t i o n of such Green ' s f unc t i ons and some of t h e i r a s y m p t o t i c p rope r t i e s for la rge m o m e n t a . The t h r e e p o i n t f unc t i ons cons idered here c o r r e s p o n d (1) to t h e a p p r o x i m a t e sum of t h e a s soc ia t ed series of all F e y n m a n g r a p h s w i t h o u t v a c u u m p o l a r i z a t i o n inse r t ions , b u t w i t h t h e inc lus ion of self i n t e r ac t ions .

The micellar phase separation (cloud-point transition) of non-ionic surfactants is studied on the basis of a statistical theory, of liquids. The low value of the critical concentration is explained by the presence of an extended repulsive intermicellar interaction due to a region of structured water. Excellent agreement with experiment is found for the polyoxyethylene surfactants C 12 E 8 and C 6 E 3 . Our model can give a closed solubility loop with a very different value of the concentration of the upper and lower consolution points. We study, also the osmotic compressibility and second virial coefficient and the correlation length.

The activity at 558 K for the CO H 2 reaction over 10% Fe TiO 2 catalysts is lower after reduction at 773 K than after reduction at 558 K. Subsequent oxidation of the high-temperature reduced catalyst restores its activity to that which existed after low-temperature reduction. We consider three catalysts: one reduced at 773 K oxidized at 673 K, and then reduced at 558 K (ROXR); one oxidized at 673 K then reduced at 558 K (OXRD); and one simply reduced at 558 K (RDOY). The turnover rates for the CO H 2 reaction at 558 K are about 100 h− for each of these catalysts. The bulk compositions measured by Mossbauer effect spectroscopy (MES) are similar for the three catalysts before use. However, the rates of carburization measured by MES are lower for the two oxidized catalysts than for the RDOY catalyst. Also, the surface carbon accumulated on the two catalyst. We propose that the residual difference among these catalysts can be explained by the presence of subsurface oxygen.

The low-density expansion and a new integral equation have been used to calculate the pair correlation function and several related quantities for krypton, using realistic pair potentials and several models for the three-body potentials: the Axilrod-Teller-Muto model, the multipolar model up to the triple quadrupole term and the Loubeyre model. The results are compared with experimental data in some detail. The models describe the three-body effects in correlation functions in a qualitative sense, but quantitative differences are observed, suggesting that shorter-ranged effects must also be included.

For fcrmion-fermion elastic scattering with Abelian vector-gluon exchanges, some progress has recently been made in understanding the high-energy fixed-angle behaviour. CANDY (1) conjectured that, for generalized ladder exchanges, a suitable (( e ikonal , ansatz should give the correct leading asymptotic behaviour. In a subsequent work (2), the assumptions made by CARDY on what should be the dominant large-momentum flow were shown to be correct, order by order. A consequence of this ~( eikonalization ~) is that important cancellations take place between the leading contributions of ordinary ladder graphs and those of crossed ladder graphs. As a result of such cancellations, in the leading logarithm approximation, the dominant contribution to the sum of all graphs of a given order in the coupling constant g is due to vertex corrections to onegluon exchange. In the leading logarithm summation (LLS) to all orders in g, one then expects a behaviour, for the elastic-scattering amplitude ~#(s, 0) as s ~ oo with fixed centre-of-mass scattering angle 0

The crossover modified-hypernetted-chain equation, extended to take into account three-body forces, is tested against recent simulation results for realistic models of krypton and xenon which include also the three-body Axilrod-Teller interaction ${v}_{\mathrm{AT}{}^{(3)}}$. The effect of ${v}_{\mathrm{AT}{}^{(3)}}$ on g(r) is reproduced so well that this equation can also be used in the framework of inversion of structural data to separate the true two-body contribution out of the extracted effective potential. We also study the way ${v}_{\mathrm{AT}{}^{(3)}}$ influences the critical point of the liquid-vapor phase transition for Ar, Kr, and Xe. We find that both ${\ensuremath{\rho}}_{c}$ and ${T}_{c}$ are lowered by ${v}_{\mathrm{AT}{}^{(3)}}$ and that the small deviations from the law of corresponding states are as much due to ${v}_{\mathrm{AT}{}^{(3)}}$ as to the different shape of the pair interaction.

The aim of this study was to determine if Rituximab coated Biodegradable Nanoparticles (BNPs) loaded with Chlorambucil and Hydroxychloroquine could induce apoptosis of B-Chronic Lymphocytic Leukemia (B-CLL), MEC-1 and BJAB cells in vitro and evaluate their toxic and therapeutic effects on a Human/Mouse Model of Burkitt Lymphoma at an exploratory, proof of concept scale. We found that Rituximab-Chlorambucil-Hydroxychloroquine BNPs induce a decrease in cell viability of malignant B cells in a dose-dependent manner. The mediated cytotoxicity resulted from apoptosis, and was confirmed by monitoring the B-CLL cells after Annexin V/propidium iodide staining. Additional data revealed that these BNPs were non toxic for healthy animals, and had prolonged survival in this mice model of human lymphoma.